Curtain rods which are sold for domestic use must be adjustable to a variety of sizes of window, door and other openings. Commonly, rods have been adjustable within limits, so a particular rod product may be made to fit a particular opening size at the time a user installs a rod.
The present invention relates to curtain rods comprised of round two-piece hollow tubes, where one part telescopes within the other part, so the length is adjustable to fit a window or door opening. Many such prior art rods run between opposing side brackets. The brackets may be screwed or nailed to the opposing sides of the frame of the opening. However, for convenience of installation, and to avoid damage to the frame, curtain rods have heretofore been held in place by means of frictional engagement of the rod ends with the opposing sides of a window frame or the like. It follows that there must be means for exerting sufficient force against the window frame surfaces, so the weight of the rod and any associated curtain or other window treatment is supported by frictional engagement; and, that means must be compatible with the need for having adjustable length of the rod.
Another market place need is that a curtain rod of the foregoing type should be suited for easy installation by an average householder without the use of tools. While there are various designs which are previously known for accomplishing the needs, including those which include tubular rods which have internal springs or mechanical locking mechanisms, there is a continuing need for improved designs which have a better combination of simplicity of installation, good functionality, and economy of manufacture.